Proteins
Proteins are a cornerstone of modern biotherapeutics, providing innovative treatment options across multiple therapeutic areas including cancers, autoimmune disorders, genetic conditions, diabetes and infectious diseases. Their therapeutic potential lies in their ability to interact with biological systems in highly specific ways.
However, proteins also present significant challenges for development. Their large molecular size, structural complexity and heterogeneity due to post-translational modifications, combined with their sensitivity to environmental conditions, demand a tailored and expert analytical approach. Only a comprehensive and customised strategy can ensure the reliable confirmation of structure, purity and potency, while addressing critical attributes such as stability, aggregation and immunogenicity.
To succeed in developing protein-based drugs, you need a partner with the expertise, technologies and regulatory know-how to deliver robust data and accelerate your pathway to market.
Unlocking therapeutic potential through tailored analytical solutions
We offer a comprehensive analytical package on a single site, covering CMC and bioanalysis services to address every aspect of protein therapeutic development.
Our expertise extends across the full diversity of protein modalities, including fusion proteins, PEGylated proteins, mAbs/ADCs and oligosaccharide-conjugated proteins. Leveraging advanced technologies and deep scientific know-how, we adapt our strategies to the specific complexity of each molecule, ensuring meaningful data to support informed development decisions.
Related products
Analytical challenges we help you solve
Proteins present a wide range of analytical challenges due to their structural and chemical diversity.
At Quality Assistance, we bring clarity to this complexity by ensuring reliable characterisation at every stage of development. We confirm primary and higher-order structures, monitor glycosylation patterns and charge/size variants, binding properties, product potency and identify impurities and degradation products. We also provide absolute quantification of protein and extinction coefficient determination of biological standards, while assessing stability under ICH-compliant and customised conditions.
| Intact protein molecular weight | Mass spectrometry (ESI-QTOF, MALDI-TOF) / SDS-PAGE / cGE |
|---|---|
| Isoforms | Mass spectrometry (ESI-QTOF, MALDI-TOF) / IEF / icIEF / (U)HPLC (IEX, RP, SEC, HIC) / 2D gel / Peptide mapping |
| Peptide mapping | UPLC (UV, QTOF) / MALDI-TOF |
| Immunological identification | ELISA / ECL (MSD) / Luminex / Western blotting / SPR (Biacore) / BLI (Octet) |
| N- and C-terminal sequencing | Peptide mapping (UPLC-QTOF) / MALDI-TOF (ISD) |
| Protein quantity | BCA / Lowry / Bradford / UV / (U)HPLC (UV) / SoloVPE |
|---|---|
| Absolute protein content determination | ICP-MS (S, isotope dilution) |
| Determination of extinction coefficient | UV + ICP-MS (S, isotope dilution) |
| Mass distribution profile | Mass spectrometry (ESI-QTOF, MALDI-TOF) / SEC-(U)HPLC (UV, RI, MALS) / AF4 |
|---|---|
| Structural integrity | CD / FT-IR |
| Isoforms | IEF / icIEF / (U)HPLC (IEX, RP, SEC, HIC) / 2D gel / Peptide mapping / Mass spectrometry |
| Aggregation, fragments and particle size distribution | SEC-(U)HPLC (UV, RI, MALS) / AF4 / cGE / DLS / SDS-PAGE / Imaging Particle Analysis |
| Glycosylation patterns | UPLC (FLUO, QTOF) / MALDI-TOF / CE (LIF) / GC (MS) |
| Disulphide bridges | Peptide mapping / cGE / SDS-PAGE |
| Free thiols | Fluorescence (NPM) / UV (Ellman, DTNB) |
| Degradation patterns (oxidation, deamidation, Lys-term truncation, etc.) | IEX / RP-(U)HPLC / SEC-(U)HPLC / SDS-PAGE / (U)HPLC (MS) / CE (icIEF, cGE) / 2D gel / Peptide mapping (MAM using HRMS) |
| Immunoassays / Cytotoxicity / Proliferative / Cell death / Cell migration / Cell receptor binding and activation / Reporter gene assays / Enzymatic activity | ELISA / ECL (MSD) / Luminex / Cell-based assays / FACS / SPR (Biacore) / BLI (Octet) / Gyrolab |
| Residual solvents | HS-GC (FID, MS, ECD) |
| Residual proteins (including HCP, protein A, purification Ab) | ELISA / ECL (MSD) / Luminex / Gyrolab / UPLC (MS/MS) / Western blotting / 2D gel / 2D-DIGE |
| Buffer components (including BSA, Tween, β-OG, Antibiotics) | ELISA / ECL (MSD) / Colorimetry / (U)HPLC (UV, MS, RI, ELSD, CAD) |
| Antifoam agents (PPG, PEG, silicone oil) | ICP (MS, OES) / (U)HPLC (ELSD, CAD) |
| Residual DNA | qPCR / ddPCR / PicoGreen |
| Elemental impurities | ICP (OES, MS) |
| Microbiology | Bioburden / Sterility (filtration, direct inoculation) |
| Endotoxins and pyrogens | LAL (kinetic, end point) / rFC / MAT |
| Leachables | GC (FID, ECD, MS) / ICP (OES, MS) / (U)HPLC (UV, ELSD, CAD, MS) |
|---|---|
| Container Closure System Integrity | Bubbling / Dye ingress / Microbial ingress |
| Cytotoxicity / Biological reactivity | Cell-based assays / USP <87> |
| Break Loose and Glide Force (BLGF) for prefilled syringes |
Platforms and technologies
At Quality Assistance, we combine scientific depth with state-of-the-art instrumentation to address the complexity of protein therapeutics. Our technology platforms are designed not only to deliver robust, regulatory-compliant data but also to accelerate your development decisions with clarity and confidence.
- Advanced mass spectrometry workflows enable in-depth characterisation at multiple levels – from intact protein to peptide mapping and post-translational modifications, including innovative Multi- Attribute Monitoring (MAM) approaches.
- Comprehensive glycosylation profiling provides a detailed picture of N- and O-glycans, as well as sialylation and monosaccharide content, supported by orthogonal LC-MS approaches that cover the full spectrum from released glycans to intact protein level.
- Aggregation and particle analysis with SEC-MALS, AF4-MALS, Dynamic Light Scattering (DLS) and flow imaging allows reliable detection of fragments, soluble aggregates, and sub-visible particles, critical for ensuring safety and efficacy.
- Higher-order structure analysis and epitope mapping using Circular Dichroism (CD), FT-IR, and HDX-MS deliver unique insights into protein folding and stability and are particulary valuable in comparability and biosimilarity studies.
- In vitro potency and binding assays, including Biacore (SPR), Octet (BLI), Gyrolab, and functional cell-based assays, provide robust evidence of biological activity and mechanism of action.
- Absolute protein quantification by ICP-MS, based on sulphur content, offers unmatched precision and accuracy (compared with conventional amino acid analysis) for qualification of biological standards.
Related services
Bioanalytical services
The bioanalysis of proteins requires highly selective and sensitive methods due to their structural complexity and potential for immunogenicity.
At Quality Assistance, our GxP-compliant bioanalytical services cover the full development continuum, from non-clinical to clinical phases.
We provide quantitative analysis of proteins and metabolites in biological matrices, conduct pharmacokinetic and toxicokinetic studies and perform biomarker analysis with multiplexed immunoassays and LC-MS/MS platforms.
Our expertise also extends to immunogenicity assessment through tiered anti-drug antibody testing strategies, including screening, confirmatory and characterisation assays. In addition, we support immunomonitoring studies to evaluate immune responses and their impact on therapeutic efficacy and safety.
Why (bio)pharmaceutical companies choose us
Working with Quality Assistance means reliable data, proactive support and full project traceability via our in-house LIMS.
From method development to validation, QC testing and reporting, our team of experts ensures:
- ADC-focused scientific expertise: with over 20 years of experience in complex biologics, our team has developed deep expertise in ADCs, including diverse conjugation strategies and payload formats.
- End-to-end analytical capabilities under one roof (facilities dedicated to highly-potent / cytotoxic compounds including OEB5): from method development to release testing, we offer a fully integrated analytical workflow for ADCs. All required analytical tests are performed in-house, ensuring consistency, speed and scientific continuity throughout your project.
- State-of-the-art instrumentation for ADC characterisation: we continuously invest in advanced technologies to support the comprehensive analysis of ADCs, from structural integrity to potency and isoform / impurity profiling.
Driving protein development with reliability and compliance
With Quality Assistance, you gain a partner that combines CMC and bioanalysis services in one integrated package, backed by over 40 years of expertise and full regulatory compliance (EMA, FDA, ICH). By centralising all required analysis within one single environment, we help you navigate complexity with confidence, reduce development risks and accelerate your path to market.
Discuss your project with an expert